1. Field of the Invention
This invention relates to an inflatable flexible pouch that has a valve element which enables the pouch to be inflated by mouth or with a tube, such as a straw, and the valve element acts as a check valve to automatically seal the inflated pouch and thus retain it in an inflated condition.
2. Description of Prior Art
Conventional flat check valves including two or more layers of film are known. Such conventional check valves are attached, usually heat sealed, at a peripheral edge of a plastic balloon. However, such conventional valves are manufactured at a location separate from the balloon manufacturer and require additional labor and machinery to install them in the plastic balloon.
U.S. Pat. No. 4,983,138 discloses an inflatable container with a self-sealing valve. The container has two heat sealed film layers joined at the perimeter of the two layers. An exterior slit is formed in one of the layers. A valve film layer is positioned between the two surface layers. The valve layer is heat sealed to the bottom surface film layer from a transition point across to a stem area, leaving a gap between the seal and the transition point. Such heat seal runs in close proximity to the body edge so as to form a narrow channel, the upper boundary of which is formed by the valve layer and the lower boundary of which is formed by the bottom surface layer. Perpendicular creases which form along the container surfaces, when the container is inflated, cross the fluid channel to help seal the container.
Even in view of the known conventional flat valves and the flexible container taught by U.S. Pat. No. 4,983,138, it is apparent that there is still a need for a relatively inexpensive flat check valve that effectively seals an inflated plastic balloon, particularly over an extended time period.